Blender 2.8; Combine Cycles and Eevee render engines into single composite
This solution seems to get me 99% of what I originally asked for in the question.

Okay I got it to work, my problem was I was trying to create two different View Layers - create an additional Linked Scene instead so all your objects stay consistent between the two, in compositing make two Render Layer nodes and set each one to the respective Scenes you've rendered. Then you can alpha over the scene with the Freestyle pass and the Eevee pass.

My only problem now is that if I render both the scenes (as in neither has "Use Single Layer" clicked) it takes about 2 minutes for a very simple scene, but if I render them individually (One after another with "Render Single Layer" clicked) they each respectively take a second or two. It seems that when I render them both concurrently the Cycles pass still path traces the objects even with all the passes and ray visibility disabled. Not sure if I am missing something or if this is a possible bug.